Originally the array looks like this:

Richard: 95
Sherwood: 82
Toni: 98
Franz: 87
Melissa: 75
Roddy: 85

After sorting the array by value using arsort(), the array looks like this:

Toni: 98
Richard: 95
Franz: 87
Roddy: 85
Sherwood: 82
Melissa: 75

After sorting the array by key using ksort() the array looks like this:

Franz: 87
Melissa: 75
Richard: 95
Roddy: 85
Sherwood: 82
Toni: 98